This invention relates generally to processor-based systems and in particular embodiments to the use of wireless keyboards in connection with processor-based systems.
Wireless keyboards enable computer users to input data from positions spaced from the remainder of a processor-based system. This gives the user the additional freedom to make data entries without requiring the user to sit proximate to the processor-based system.
Each time the keyboard sends a wireless key make code to the host computer indicating that a key has been depressed, the host computer awaits a key break code indicating that the key has been released. If the key make code is not followed within a predetermined time frame by the break code, the operating system automatically repeats the key represented by the make code. The delay between the make code and automatic repeat is user configurable. This automatic repeat will stop when a break or another make code is received.
If a wireless keyboard loses its wireless link with the host computer, after sending the key make code, but before the key break code is sent, the operating system of the host computer may automatically repeat the key indefinitely. This becomes a serious problem because the keyboard may have a relatively limited effective range. If the keyboard is moved too far away from the host processor-based system, the link may be lost. Similarly, if severe interference is encountered, the link may be lost as well.
The phenomenon where the key is automatically repeated is called a typematic. The uncontrolled typematic that ensues can cause undesirable behavior on the processor-based system.
Thus there is a continuing need for ways to prevent uncontrolled typematics when using wireless keyboards.
In accordance with one aspect, a method includes communicating, over a wireless link, that a key has been operated on a wireless keyboard. A wireless signal is generated from the wireless keyboard to test whether the wireless link is still working.
Other aspects are set forth in the accompanying detailed description and claims.